Means for causing mercury to circulate while electrolyzing aqueous solutions of metallic salts.



R. CARL.

MEANS POB OAUSING MERCURY To OIROOLLTB WHILE BLEOTROLYZING AQUEOUS SOLUTION 0F METALLIC SALTS. APPLICATION FILED 601:24, 1911.:

UNITED sTArFsrFNT oFFioF.

RUDOLF CARL, OF SCHMARGENDORF, NEAR BERLIN, GERMANY, ASSIGNOR T0 SIEMENS 8c HALSKE, A. G., OF BERLIN, GERMANY, A CORPORATION 0F GERMANY.

MEANS FOR CAUSING MERCURY T0 CIRCULATE WHILE ELECTROLYZING- AQUEOUS SOLUTIONS OF METALLIC SALTS.

Specification of Letters Patent.

Patented May *7, 1912.

Application filed October 24, 1911.k Serial No. 656,506.

To all whom 'it may concern.'

Be it known that I, RUDOLF CARL, a subject of the Emperor of Austria-Hunga-ry, and residing at Schmargendorf, near Berlin, Germany, have invented certain new and useful Improvements in Means for Causing Mercury to Circulate l/Vhile Electrolyzinv` Aqueous Solutions of Metallic Salts, o which the following is a specica tion.

My invention relates to the circulation of mercury when electrolyzing aqueous solutions of metallic salts.

lVhen electrolyzing aqueous solutions of metallic salts by means of a mercury cathode, c. g. in the chlorin-alkali electroyltic process, as is wellknown thel uniform and uninterrupted movement of t-he mercury is of great importance. In the processes customary at the present day the mercury is preferably conveyed by mechanical means, but large quantities of mercury are then requisite.

A primary object of my invention is to produce a circulation of the mercury by means of the action of heat. To this end, I arrange the mercury in a hydrostatically closed ring for example, by connecting` the two sides of a cell by a pipe. For bringing about the circulation I produce dilerences of temperature in the ring ot' mercury either by cooling the mercury at one place, or by supplying heat to another place, or by using both means simultaneously. The mercury at the place subjected to a higher temperature is expanded and is contracted at the part ot lower temperature, whereby a unitorm circulation is produced in t-he hydrostatically closed ring. The mercury is pref* erably cooled in proximity to the outlet ot the cell and heated in proximity to the inlet. The cooling may be brought about by any cooling agent, e. g. water, within or wit-hout the cell, and the heating by special heating means of any kind in the event of the heat occurring during the electrolysis not suiiicing.

In carrying the process into practice only small quantities of metal are required; a layer about 5 mm. deep on the bottom ot the cell suffices. Also, the amount of energy requisite for producing the circulation is exceedingly small as the mercury is in hydrostatic equilibrium and a disturbance of this equilibrium, i. e. circulation, occurs owing to a very slight change in the temperature conditions.

One illustrative embodiment of the invention is represented by way of example in the accompanying drawing in vertical sectional elevation.

Referring to the drawing, a designates a cell containing mercury Z) on the bottom thereof. The two sides of the cell are connected with one another by a pipe o. The arrows indicate the direction' in which the mercury circulates.

Z designates heating means and e cooling means.

The remaining parts of the plant are nonessent-ial to the understanding ot' the invention and have therefore been omitted for the sake of clearness. The hydrost-atically closed ring may of course include a plurality of cells.

I claim l. In a plant for electrolyzing aqueous' solutions of metallic salts, the combination with a cell containing mercury of a hydrostatically closed mercury ring connected with said cell, and means for producing dif4 'terences of temperature in the mercury in the ring near the points of connection.

2. In a plant for electrolyzing aqueous solutions of metallic salts, the combination with a cell containing mercury, of a pipe connecting two sides of the cell below the level ot the mercury, and means for cooling, the mercury in the pipe near one side of the cell.

3. In a plant tor electrolyzing aqueous solutions of metallic salts, the combination with a cell containing mercury,` of a hydrostatically closed pipe connecting two sides of the cell below the level of the mercury, and means for heating the mercury in the pipe near one side ot the cell.

4. In a plant for electrolyzing aqueous solutions ot' metallic salts, the combination with ay cell containing mercury, of a pipe other side of the cell.

connected with two opposite sides of the cell name to this s below the levelel of t e mercury, cooling two witnesses. means `for coo in g the mercury in the pipe near one side of the cell, and heating means RUDOLF CARL' for heatingmercury in the pipe near the Witnesses:

HENRY HASPER, WOLDEMAR HAUPT.

peciication in the presence of In testimony whereof, I have signed my Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents.

Washington, D. C. i 

